1. Field of the Invention
The present invention relates to the use of certain ionic or non-ionic derivatives of undecylenic acid or undecanoic acid for eliciting a pediculicidal response.
This invention also relates to novel pharmaceutical compositions well suited for treating infestations caused by pedicular parasites.
2. Description of the Prior Art
The origin of pediculosis is lice, a parasite exclusive to man and which is essentially classified into three species:
(1) Pediculus humanus, var. capitis, or head louse, PA1 (2) Pediculus humanus, var. corporis, or body louse, PA1 (3) Phtirius inguinalis, or pubic louse. PA1 (i) DDT (dichlorodiphenyltrichloroethane), which is an irritant, promotes changes in blood composition and number of blood cells, as well as affecting the hepatic and central nervous systems; PA1 (ii) Hexachlorohexane and lindane, which are irritating to the skin, the mucous membranes and the eyes and for which certain intoxications have been indicated (vomiting, diarrhea, hyper-excitability, convulsions, acute pulmonary oedema, coma); PA1 (iii) Natural or synthetic pyrethrins, such as bioallethrine, bioresmethrine, neopyramine, sumithrine, D-phenothrine, which can engender allergies and are sometimes irritating; PA1 (iv) Benzyl benzoate and malathion, which have an irritating effect on the eyes and the scalp.
Cases of pediculosis which are quite frequent, both in their endemic and epidemic forms, not only cause irritation and lesions from the resulting scratching, but lice are also vectors of certain disease states such a exanthematic or epidemic thyphus and recurrent fever.
Representative currently employed pediculicides, which are indeed polyvalent anti-parasitic agents comparable to insecticides employed for agricultural treatments, uses include, in particular, compounds of the organochloride or organophosphide family as well as the pyrethrins. Such compounds are variously formulated, notably as powders, lotions, shampoos or sprays. Each of these forms presents advantages and disadvantages. Thus, powders which, a priori are less toxic and are easy to use require a special item of headwear to be worn. Lotions, which are easy to apply and homogeneous, require prolonged contact and rinsing and can, moreover, because of the fact that they tend to run, promote irritation of the mucous membranes. Shampoos promote adverse effects because of the detergent included therein and they also require a relatively long contact time. Aerosols elicit a dissolving action on the lice and their eggs, but they do not permit controlled application, and, moreover, they can initiate certain eye irritations.
The pediculicidal compositions to date generally used include the following compounds:
The incidents indicated are relatively rare and are practically non-existent under normal conditions of use, and have essentially occurred in infants. The have nevertheless occurred and hence can signify serious risks. In addition to such risks, current products frequently elicit skin irritations.
Such existing products suffer from the added disadvantage of displaying scant ovicide activity, namely, they are only slightly active on the eggs of lice (nits). Indeed, the currently employed compositions do not permit infestations by pedicular parasites to be combatted effectively, whether they be in the adult or larva (egg) state.